Magneto



H. F, GEIST.

MAGNETO.

APPLICATION men 1AN.a.19\1.

H. F. G ElST.

marmo.

APPLICATION FILED MN. 3| |91?. y

Patented Mar. 23, 1920.

2 SHEETS-SHEET 2.

w27-TW r AT TRNYEI' UNITEp snirns` PATENT OFFICE.

7b all whom it may conf-ern.'

Be it'lknown that I, HARRY 1".'GE13'1, ai

citizen of thc'United States, and resident of ^`Racll1e,f in 'the'county'of Racine and State 6 lfjll'iscnsi'nl' have invented new'and useful `hnfrovenlents jn Magnetos",v of which the fl divin" i's a descriptionfreference being i l*The'-invention is"inore particularly de- 'signed to'provide Iam'agneto of the armatuie Fiswolin'cltype in' which by'ra'son of the con- 4"" clalffeatures hereinafter set fortlrand more4 particularly defined clu'sion'hereof.

Int-he drawings:l

Figure 1 is afront view of the device, part byclair'ns at the con- M1of-the-interrupter adjusting lever beinelr broken away;

Fi i 2 is a."section taken on the line of Fig; 1,' parts being broken away;

Fign 3 is a section taken fonthe line 3, El .iijofivFlgg' 35 *Figty 4 1s a section'taken on the line 4 1 of Fxgly r- Wig. 5 a-section taken on the line 5- ofgFlg. I; Y il Fi 6is a diagrammatic view of the electrica circuiti?" "For convenience in` ex )lanation the mechanical construction of t e frame, field, armature and -interrupter will be described f 1" first and' the circuit connections ofthe machine together with its operation thereafter.

The frame consists of the portion 10 havingabuse 11 adapted to be mounted on any sultable support adjacent to the engine to wir Y which the"magneto is operatively 'connected'. The field consists of A )ole shoes desig-l nated as'a whole as 1,2 an ermanent magnets 213 'connected to said po e'shoes and the framecrl() by metal strips Y14 surrounding' said magnets and eonnectedat their lower ends to the frame 10 by anysuitable means1 such as screws '15.

l lThe pole shoes are of special construction Specition of Letters Patent.

Application led January 8, 1917. SerialNo. 141,230.

' The invention re etes magnetos for igi IiARRYF. GEIST, OF RACINE, WISCONSIN.

MAG-NETO.

Patented Mar. i23, 1920.

. which travel through the field :it rightan les v to the plane ofsaid laminse and thus re uce 7o the iron losses in the field. Holes orirecees 19 are provided in the bloc-ks 17 to reduce the V coeiicientof self'in'ductionof the secondary` winding and by so doing reduce 'theftime constant of the secondary winding. For convenience in manufacture the' frame 10- is cast around the laminzc 16 and blocks 17' by a 'die-casting method so that the whole forms one unitary structure having the bore. 20 therein for receivingv the armature gand its bearings., A

Theuarmature consists of an I-shaped core formed 'by I-shaped` soft iron laminac 21 secured by rivets 22 to I-shaped solid iron pieces Q3 having extensions 24 and 25 shaped to correspondto the upper' and lower curved ends of the Igshaped core and further .secured by rivets 26 to form an integral core Eand 'further consists Vof vthe armature windingshereinafter described. The'lanii-l 490 nu" are provided -in the `core lto 'reducetlie iron losses by breaking up the eddy 'currents set up therein.A The solid iron blocks'of the core are provided with holes 27 to reduce the coefficient of self induction of theI secondary winding to thereby reduce the time constant of the secondary winding. It will be noted from Fig. 3 that the ends of the core overlap the ends of thc pole pieces, just. before the break in the magnetic field is made and when the web of the I is disposed at right angles to tlul pole pieces the magnetic flux will be the greatest.

'l`hc nrinature windings comprise a primary coil 2S which iiisulatedfroni thecore 105 h v insulation Q9 and a Secondary coil 30A insulated from the primary and from` the core, both coils .being wound around the web portion of the I-slmped core, theprimary being Ls rrolu'ided to thecore by having.; one cud (not. shown) connected to a grounding screw 3l as is usual in devices of this kind.-

The armature is provided with brass 01' other non-magnetic end plates 32 and 33 suitably secured thereto, the plate 32 having extends, the shaft being connected up to any ing 46 of insu suitable source of power for rotating it, as by a gear connection with the engine and the bushing 35is journaled in a ball bearing jonrnn 39 mounted on `a frame end plate 40 secured to the ,frame 10 by screws 41, the end' plate37 being secuied in a similar manner. On the removall of the end lates 37 and 40, the whole armature may e withdrawn from the frame. i

The primary circuit is also provided with a. condenser 42 mounted in the armature on the plate 33 by means of a threaded plate 43 and bolt 44 which also serves to secure the interruptor in position as hereinafter describe-d, the condenser'being insulated from the conductor parts by a plate 45 and bushating material. f

I The interrupter consists of a metal disk 47 havinga tapered projection 48 .seated and keyedina tapered seat 49 of the bushing: 35nnd having mounted thereon but insu ated therefrom a contact carrying member 50, the bolt i4-passing through aperv tures in the member 50 andzthe disk tov clamp said parts to said bushing together with the condenser 42, the bolt being insulated from the disk 47. A contact lever 51 is pivotally mounted on a bushing 51 of insuating material on a stud screw 52 secured to the disk 47 and is provided with a contact oint 53radapted to engage with an adjusta le contact 54 mounted in the member 50. The'eontacts 53 and 54 u'e normally held together by means of a spring 55 secured to -the lever 51 and to the. disk 47 and the circuit is interrupted by tweaking the contact by means of a clam 56 carried on an adjustable sleeve 57 -mounted on a cylindrical boss"58 of thc end plate 40 and provided with an operating lever 59. said cam adapted to contact with a cam block 60 on the lever`l 51. during the rotation of said level' with the armature. the part of .the lever 51 carrying thc-block 60 moving inwardly while in contact with the cam 56 and the other end of the lover carrying the contact 53 movlng outwardly to break the circuit.

62 through end'plate 32. A contact-finger .64 yieldingly slidably mounted in a binding post 65 contacts with the ring 61, the post,65 and finger 64 bein insulated from the frame by a socket mem r 66 of insulating nmterial. The contact finger 64 is adapted to be connected with the ungrounded terminal of thespark plug 67.

'A circuit wire 68 connects the 4primary coil withone side of the condenser.I and thence to the insulated .interrupter point through holt 44, and a circuit wi 69' grounds the other side'of Vthe condeli r to the armature core. while the interru ter spring 55 grounds the interrupter and s iort circuits the primar.;Y Windin and the condenser when the points 53 an 54 are in con- ,tact YThe discharge brush 70 grounds the that the primary winding is connected in series 'with the intcrrupter and is grounded on Vthe core. The condenser is shunted across the primary circuit, one side bein connected to rimary circuit by the wire 68 and the otlier side being grounded on the core by the wire 69. One side of the secondary coil is connected to the primaryI and the other end-of this coil is connected to the ungrounded electrode of the spark plug 67 through the wire 63, ring 61, finger 64, .t 65 and the wire (not shown) leading rom said post to the aforementioned electrode of the spark plug.

The operation of the device is as follows: lVhcn the armature is rotated by the shaft 34 so as 'to move the core at right angles to the position shown in Fig. 3, all the magnetic `fiux is then directed through the pole pieces. A fter the armature has moved .past the position shown in Fig. 3 and just as tinJ ends of the armature leave the ends of the pole pieces. the` cam is set by the lever 59 to more the lever 51 to open the. primary circuit at the interruptor contacts. lVhen this occurs` the current. that is generated due to the electrical short circuit of thc primary through the interruptor contact points under the assumed armature motion. is sud dcnly checked` and thc reactive iux and iti. distorting ctlcct upon the cxcitationiiux. which represent the stored electro-magnetic energy simultaneous and coincident to the current. must also suddenly disamiiear. It

successful machine as the soft iron laminas l reduce the iron losses and the holes in the solid iron parts of the pole pieces and the armature core reduce the time constant of secondary winding so that an improved transformation of energy takes place between the primary and secondary circuits.

The reason for iron losses inthe pole pieces is due to the fact that, on the closed circuit of the primary, the current set up in the primary sets up a reactive flux that crowds the main flux of the ma ets" to the edge of the pole piece from whicinthe armature is passing, and when the interrupter opens and the reactive flux suddenly disap.

pears, the main flux takes its natural ath which is then through the other ed e o the y pole piece.` The sudden change rom one edge to the other sets up eddy currents in the pole pieces that flow parallel to the axis of rotation of theA machine and by usingath laminar disposed at right angles to this h ile the eddy current losses are reduced.

the construction herein shows both lamin i and solid iron combined together, the laminations of the pole pieces are placed directly opposite the laminations of the amature and thus take care ofthe greater part ot' the fiux. 4

ln this type of machine the energ is generated and stored in the form'of a distorted magnetic field during the eriod that the primary circuit is close through the breaker and at that time the secondary is idle. (7nL the interruption of the rimary by the breaker' a transformation o energy occurs during which the energy 'passes from the primary to the secondary cir-cuit, In order that the transformation be as perfect as possible, the time constant, that is.the time it takes energy die down in the circuit, of the secondary must not be greater than that of the primary in connection with its condenser. To reduce the time constant. of the seconilary and have it equal to that of the rimaly l have provided the recesses 19 in t e solid iron pieces 17 of the field and tht` holes 27 in the. armature core.

The advantages of having a secondary circuit with the proper time constant is not to either build up or 4comprising u apieces, said pole piecesjconsisting of con.-

only the fact that more energy will enter -the spark but that the size of the condenser necessary will be reduced, a cleaner action at the breaker points will result and the number of turns of' wire reuired in the sec ondary coil will be reduce It willfbe seen that certain of the features of construction of this invention may be used in the low tension form of magneto Where the armature carries only one coil and no condenser in which case the apertures in the armature and field would be omitted.

I am aware that the specific construction liereindescribed, is subject to modification and change and I therefore desire it to be understood that such modifications and changesas come Within the scope of the ap pended claims are within the spirit of my invention.

What I claim as my invention is:

1.111 a wound armature type magneto, the -combina-tionl of a revoluble armature carrying primary and secondary coils, a field structure comprising a frame, field magnets and pole pieces, said pole pieces including solid iron blocks having apertures therein to reduce the time constant of the secondary, substantially as described.

2. In a wound armature type magneto, the combination with a field structure, of a revo-V luble armature including primary and sec-4 oiidarrxv coils and a core, said core including solid iron parts havingapeitures therein to reduce the time constant of the secondary, substantially as described..

3. In a. wound armature type magneto, the combination of a revolublc armature includ-1 ing primary and secondary coils and a core including solid iroir parts having apertures' therein for reducingr the secondary circuit and a, field structure comprising a. frame, eld'magnets and pole pieces inc apertures therein for reducing the time constant of the secondary circuit.

4. In a Wound armature type magneto, the combination of al rcvoluble armature c omprising primary and secondary coils, wound parallel to its axis, and a core comprising connected together soft iron lamin disposed at right angles to the armature and solid 'iron partsl havin apertures thereinl for the purpose describe and afield structure iiected together soft 4iron laminee disposed at right angles to the axis of rotation of the,

the time constant ofV ioo u ding solidiron parts having;V

a frame, field magnets, and pole armature and opposite to the laminat-ed orl tion' of the core vandwsolid iron blocks aving apertures therein.

In testimony whereof, I affix myy signature.

HARRY F. GEIST, 

